underwater infrastructure and underwater city of the future · 2017-09-13 · nilsson, l., ngo, m....
TRANSCRIPT
Underwater Infrastructure and Underwater City of the Future
New Concrete, Reinforcing Materials and Structural Consideration
School of Civil and Environmental Engineering
Research Team
A/P Susanto Teng
Dr. Liu Yu
Dr. Soerya Widjaja
Mr. Sabet Divsholi Bahador
Dr. Kondraivendhan Balakrishnan
Mr. Lim Tze Yang Darren
Mr. Rhahmadatul Hidayat
Mr. Vu Duc Hieu
Mr. Ng Jun Kai Niki
Mr. Jimmy Chandra
Overview
Topics For Today
1. Durability and Properties of NTU's Ultra
Durable High Performance Concrete
2. Design Considerations for Structural
Members made of Ultra Durable High
Performance Concrete
3. Numerical Modeling of Ultra-Durable
Reinforced Concrete Plates and Shells for
Underwater Structures
Durability and Properties of NTU's Ultra Durable High Performance Concrete (UDHPC)
presented by
Sabet Divsholi Bahador
Research Associate
Mr. Lim Tze Yang Darren
Dr. Kondraivendhan Balakrishnan
Associate Professor Susanto Teng
School of Civil and Environmental Engineering
8th February 2012
Content
• The Criteria for UDHPC
• The Mechanical and Durability Properties
• Service Life Analysis of Our UDHPC
• Development of Durability Guidelines
The Criteria for UDHPC
Fresh Concrete Properties
• Slump and Flowability
• Workability
Heat of Hydration
The Criteria for UDHPC
• Mechanical Properties
Compressive Strength
Flexural Strength
Modulus of Elasticity
Creep Shrinkage Fire Resistance
The Criteria for UDHPC• Durability aspects
Electrical Resistivity Test
Rapid Chloride Migration Test and Rapid Chloride
Permeability Test
Drying Rate Corrosion Rate
What are the Common Ingredients of
UDHPC
Normal Sand 20 mm (aggregate …)
Cement
Superplasticizer
What are the Common Ingredients of
UDHPCMineral Admixtures …
Ground Granulated Blast-Furnace Slag (GGBS) and UFGGBS
Undensified Silica Fume (USF) and Condensed Silica Fume (CSF)
What are the Variables
Water / Cementitious Ratio (w/c)
Aggregate / Cementitious Ratio (a/c)
Mineral Admixture Replacement (type and percentage)
Other Parameters
Types of Rebar (Carbon Steel, Stainless Steel 304 and Stainless
Steel 316)
Steel Fibre PP Fibre
Content
• The Criteria for UDHPC
• The Mechanical and Durability Properties
• Service Life Analysis of Our UDHPC
• Development of Durability Guidelines
Slump Test
Casting Slab
Filling a Box
Is This Self Compacting Concrete
(SCC)?
• No
• The flowability is similar to SCC.
• The w/c ratio is 0.25 instead of 0.35-
0.45 for SCC.
• We can use normal fine and normal
coarse aggregate.
Mixes studied ….
Mix w/cTotal
CementitiousOPC UFGGBS GGBS USF CSF
1 0.35 448 448 0 0 0 0
2 0.35 444 311 133 0 0 0
3 0.28 522 522 0 0 0 0
4 0.28 518 363 155 0 0 0
5 0.25 585 527 0 0 58 0
6 0.25 580 348 174 0 58 0
Mixes studied ….
Mix w/cTotal
CementitiousOPC UFGGBS GGBS USF CSF
7 0.32 454 454 0 0 0 0
8 0.25 584 409 175 0 0 0
9 0.25 583 320 174 87 0 0
10 0.25 582 320 262 0 0 0
11 0.25 590 590 0 0 0 0
12 0.65 342 342 0 0 0 0
13 0.25 582 320 0 262 0 0
How Good Is Our UDHPC?
0
20
40
60
80
100
120
140
160
0 20 40 60
Co
mp
res
siv
e S
tre
ng
th (
MP
a)
Curing (days)
G 35
UDHPC
How Good Is Our UDHPC?
0
2
4
6
8
10
12
14
0 20 40 60
UDHPC
G 35
Curing (days)
Fle
xu
ral S
tre
ng
th (
MP
a)
How Good Is Our Concrete?
Rapid Chloride Migration Test (RCMT)
Constant Voltage 10 % NaCl and 0.3 NaOH
How Good Is Our UDHPC?
Rapid Chloride Migration Test (RCMT)
0 5 10 15 20
Low
Moderate
High
Very High
Extremly High
D28×10-12
m/s
Resistance to Chloride Penetration
Nilsson, L., Ngo, M. H. and Gjørv, O.E., “High-performance Repair Materials for Concrete Structures in the Port of
Gothenburg”, Second International Conference on Concrete Under Severe Conditions: Environment and Loading, Vol.
2, 1998, pp. 1193–1198.
How Good Is Our UDHPC?
Rapid Chloride Migration Test (RCMT)
10.2
7.9
6
3.8
1.71
0.11 0.07 0.010
2.5
5
7.5
10
12.5
3 28 56 90
G 70
UDHPC
Extremely High
Very High
High
Moderate
98.6% Reduction
How Good Is Our UDHPC?
Rapid Chloride Permeability Test (RCPT)
Understanding AASHTO T277 and ASTM C1202 Rapid Chloride Permeability Test, Concrete Bulletin
How Good Is Our UDHPC?
(RCPT)- Chloride Permeability
27002500
2000
1750
870
120 98 470
500
1000
1500
2000
2500
3000
3 28 56 90
G 70
UDHPC
Negligible
Very Low
Low
Moderate
95.2% Reduction
How Good Is Our UDHPC?
Electrical Resistivity (Corrosion rate)
0 5 10 15 20 25
Low
Moderate
High
Very High
KΩ.cmACI Committee 222, Protection of Metals in Concrete Against Corrosion, ACI
222R-01, 2001, pp. 41.
How Good Is Our UDHPC?
Electrical Resistivity (Corrosion rate)
30
70
1700
1
10
100
1000
10000
90 days
G 70
Durable Concrete
UDHPC
56 times increase
How Good Is Our UDHPC?
Direct Electrical Resistivity
G 70 at 90 days of water curing 8 kΩcm
UDHPC at 90 days of water curing 448 kΩcm
56 times increase
When we apply 60 Volts to 50 mm thick
concrete, the current passing is:
117.8 mA for G70
2.1 mA for UDHPC
Study on Creep and Shrinkage
Study on Heat of Hydration
Future Mixes…
Mix w/cTotal
CementitiousOPC UFGGBS GGBS USF CSF
14 0.25 579 232 347 0 0 0
15 0.25 579 232 0 347 0 0
16 0.25 582 320 175 0 0 87
17 0.25 582 320 0 175 0 87
18 0.25 582 320 0 175 87 0
19 0.25 580 261 0 261 58 0
20 0.25 580 261 0 261 0 58
Why Various Mixes…
Few Alternatives
• Cost Consideration
• Different Mixes for Various Exposure Conditions
Increased Safety
• Concrete Cover
• Concrete Quality
• Types of Steel Rebar
Content
• The Criteria for UDHPC
• The Mechanical and Durability Properties
• Service Life Analysis of Our UDHPC
• Development of Durability Guidelines
Deterioration of a Concrete Structure
due to Steel Corrosion
e
Service Life Analysis
All the parameters have uncertainties
• Cover Depth, Chloride Permeability, Critical Chloride
Content, Curing Duration and Time of Exposure
• Sea Water Chloride Content and Temperature
The Resistance to
withstand the
loads (R)
Monte Carlo SimulationThe
Environmental
Loads (S)
Service Life Analysis
Mix Design G 70 UDHPC
Design life 500 years
Cover depth 50 (2) mm
Temperature 30ºC
DcoefΧ10-12 m/s 7.91 (1.22) 0.11 (0.01)
t0 (age when tested) 28 days
te (age when exposed) 28 days
α (age factor) 0.4 (0.08)
Ccr (critical chloride content) 0.4 (0.08)
Cs (surface chloride content) 3.8 (0.9)
Service Life Analysis
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
0 100 200 300 400 500
Pro
bab
ilit
y o
f fa
ilu
re (
%)
Years
G 70
UDHPC
‘Nye Tjuvholmen’, Oslo (2005-?)Owner requested for 300 years design life
Service Life Analysis
Mix Design Oslo (b) Oslo (SS) UDHPC
Design life 500 years
Cover depth 100 (10) mm 50 (2) mm
Temperature 30ºC
DcoefΧ10-12 m/s 2 (0.4) 0.11 (0.01)
t0 (age when tested) 28 days
te (age when exposed) 28 days
α (age factor) 0.4 (0.08)
Ccr (critical chloride
content)0.4 (0.08) 2 (0.5) 0.4 (0.08)
Cs (surface chloride
content)3.8 (0.9)
Service Life Analysis
0
10
20
30
40
50
60
70
80
90
100
0 100 200 300 400 500
Pro
bab
ilit
y o
f fa
ilu
re (
%)
Years
Oslo (b)
Oslo (SS)
UDHPC
Content
• The Criteria for UDHPC
• The Mechanical and Durability Properties
• Service Life Analysis of Our UDHPC
• Development of Durability Guidelines
Durable Concrete Structures for the
Marine Environment
1- Durability Specifications
2- General Guidelines for Durability Design,
Quality Assurance and Preventive
Maintenance
In Collaboration with Em. Professor Odd E. Gjørv
Department of Structural Engineering, Norwegian
University of Science and Technology
Acknowledgment
o BASF Asia Pacific Pte Ltd
o EnGro Corporation Limited
o Proceq Asia Pte Ltd
o Elkem Materials SEA Pte Ltd
o Bekaert Singapore Pte Ltd
Thank You ….